Syringes are commonly filled with liquids by immersing a needle on the end of the syringe below the liquid level in a vial and then withdrawing the syringe plunger. The differential air pressure between the liquid surface and the syringe cylinder interior forces liquid up through the needle and into the syringe. The vial may include a flexible membrane over the top which is penetrated by the syringe needle and which seals upon withdrawal of the needle.
Granules such as hydroxylapatite granules and other loose solids cannot be transferred to a syringe in the manner described above for liquids because the body of granulated material will not support a differential air pressure. Instead, granules are typically transferred by pouring them from the vial into the inverted syringe. Funnels have been used to help prevent spilling the granules while they are poured. In some cases, the funnels have been attached to the vial or have been manufactured to fit closely over the syringe opening, but no existing methods integrally connect the syringe to the vial.
The existing granule transfer methods are inadequate in several respects. All the existing methods normally require two hands, while the person filling the syringe may have only one hand free. The existing methods do not include a simple method for re-transferring granules from the syringe to the vial in case too much is initially transferred to the syringe. The existing methods do not effectively prevent granules from being spilled during transfer because there is no seal between the vial and the syringe.
The method described above is also inadequate for transferring liquid to syringes without a needle. When a syringe without a needle is removed from the liquid, the large syringe opening allows the withdrawn liquid to flow out of the syringe.
This invention overcomes these inadequacies of the existing methods. Vials or bottles (both of which are referred to as "vials" herein) are fitted with an interconnect device featuring a tapered sleeve to receive the end of a syringe. The seal between the tapered sleeve and the syringe prevents any spilling. The material may be transferred with one hand by inverting the assembly. The granules may be re-transferred to the vial by simply turning the assembly right-side-up, again without spilling. A metering port in the device between the tapered sleeve and the vial interior allows close control of the transfer rate and prevents material from coming to rest in the sleeve where it could be spilled upon disengaging the syringe from the sleeve. The interconnect device is capped after removal of the syringe by a friction fit shaft or a deformable plug.
To one skilled in this art who has the benefits of the invention's teachings, other features and advantages of this invention will be apparent from the following description of the presently preferred embodiments of the invention, given for the purpose of disclosure in conjunction with the accompanying drawings.